Mystery of Faith (Mysterium Fidei)

Encyclical Letter
Mystery of FaithMYSTERIUM FIDEI

PROCLAIMED BYHIS HOLINESS POPE PAUL VI
ON SEPTEMBER 3, 1965

Pope
Paul VI by divine providence Pope, to our venerable brothers, the Patriarchs Primates,
Archbishops, Bishops and other local Ordinaries in peace and communion with the Holy See,
and to all the clergy and faithful of the world: on the doctrine and worship of the Holy
Eucharist. Venerable brothers and dear sons: Health and apostolic benediction.

The Catholic Church has always devoutly guarded as a most precious treasure the mystery
of faith, that is, the ineffable gift of the Eucharist which she received from Christ her
Spouse as a pledge of His immense love, and during the Second Vatican Council in a new and
solemn demonstration she professed her faith and veneration for this mystery. When dealing
with the restoration of the sacred liturgy, the Fathers of the council, by reason of their
pastoral concern for the whole Church, considered it of the highest importance to exhort
the faithful to participate actively with sound faith and with the utmost devotion in the
celebration of this Most Holy Mystery, to offer it with the priest to God as a sacrifice
for their own salvation and for that of the whole world, and to find in it spiritual
nourishment.

For if the sacred liturgy holds the first place in the life of the Church, the
Eucharistic Mystery stands at the heart and center of the liturgy, since it is the font of
life by which we are cleansed and strengthened to lie not for ourselves but for God, and
to be united in love among ourselves.

To make evident the indissoluble bond which exists between faith and devotion, the
Fathers of the council, confirming the doctrine which the Church has always held and
taught and which was solemnly defined by the Council of Trent, determine to introduce
their treatise on the Most Holy Mystery of the Eucharist with the following summary of
truths:

"At the Last Supper, on the night He was handed over, Our Lord instituted the
Eucharistic Sacrifice of His Body and Blood, to perpetuate the sacrifice of the cross
throughout the ages until He should come, and thus entrust to the Church, His beloved
spouse, the memorial of His death and resurrection: a sacrament of devotion, a sign of
unity, a bond of charity, a paschal banquet in which Christ is received, the soul is
filled with grace and there is given to us the pledge of future glory."[1]

In these words are highlighted both the sacrifice, which pertains to the essence of the
Mass which is celebrated daily, and the sacrament in which the faithful participate in
Holy Communion by eating the Flesh of Christ and drinking His Blood, receiving both grace,
the beginning of eternal life, and the medicine of immortality. According to the words of
Our Lord: "The man who eats my flesh and drinks my blood enjoys eternal life, and I
will raise him up at the last day."[2]

Therefore we earnestly hope that the restored sacred liturgy will bring forth abundant
fruits of eucharistic devotion, so that the Holy Church, under this saving sign of piety,
may make daily progress toward perfect unity[3] and may invite all Christians to a unity
of faith and of love, drawing them gently, thanks to the action of divine grace.

We seem to have a preview of these fruits and, as it were, to gather in the early
results not only in the genuine joy and eagerness with which the members of the Catholic
Church have received both the Constitution on the Sacred Liturgy and the restoration of
the liturgy, but also in the great number of well-prepared publications which seek to
investigate more profoundly and to understand more fruitfully the doctrine on the Holy
Eucharist, with special reference to its relation with the mystery of the Church.

All of this is for us a cause of profound consolation and joy. It is a great pleasure
for us to communicate this to you, venerable brothers, so that along with us you may give
thanks to God, the giver of all gifts, who with His Spirit rules the Church and enriches
her with increasing virtues.

However, venerable brothers, in this very matter which we are discussing, there are not
lacking reasons for serious pastoral concern and anxiety. The awareness of our apostolic
duty does not allow us to be silent in the face of these problems. Indeed, we are aware of
the fact that, among those who deal with this Most Holy Mystery in written or spoken word,
there are some who with reference either to Masses which are celebrated in private, or to
the dogma of transubstantiation, or to devotion to the Eucharist, spread abroad opinions
which disturb the faithful and fill their minds with no little confusion about matters of
faith. It is as if everyone were permitted to consign to oblivion doctrine already defined
by the Church, or else to interpret it in such a way as to weaken the genuine meaning of
the words or the recognized force of the concepts involved.

To confirm what we have said by examples, it is not allowable to emphasize what is
called the "communal" Mass to the disparagement of Masses celebrated in private,
or to exaggerate the element of sacramental sign as if the symbolism, which all certainly
admit in the Eucharist, expresses fully and exhausts completely the mode of Christ's
presence in this sacrament. Nor is it allowable to discuss the mystery of
transubstantiation without mentioning what the Council of Trent stated about the marvelous
conversion of the whole substance of the bread into the Body and of the whole substance of
the wine into the Blood of Christ, speaking rather only of what is called
"transignification" and "transfinalization," or finally to propose and
act upon the opinion according to which, in the Consecrated Hosts which remain after the
celebration of the sacrifice of the Mass, Christ Our Lord is no longer present.

Everyone can see that the spread of these and similar opinions does great harm to the
faith and devotion to the Divine Eucharist.

And therefore, so that the hope aroused by the council, that a flourishing of
eucharistic piety which is now pervading the whole Church, be not frustrated by this
spread of false opinions, we have with apostolic authority decided to address you,
venerable brothers, and to express our mind on this subject.

We certainly do not wish to deny in those who are spreading these singular opinions the
praiseworthy effort to investigate this lofty mystery and to set forth its inexhaustible
riches, revealing its meaning to the men of today; rather we acknowledge and approve their
effort. However, we cannot approve the opinions which they express, and we have the duty
to warn you about the grave danger which these opinions involve for correct faith.

First of all we wish to recall something which is well known to you but which is
altogether necessary for repelling every virus of rationalism, something to which many
illustrious martyrs have witnessed with their blood, while celebrated Fathers and Doctors
of the Church constantly professed and taught it; that is, that the Eucharist is a very
great mystery. In fact, properly speaking, and to use the words of the sacred liturgy, it
is the Mystery of Faith. "Indeed, in it alone," as Leo XIII, our predecessor of
happy memory very wisely remarked, "are contained, in a remarkable richness and
variety of miracles, all supernatural realities."[4]

We must therefore approach especially this mystery with humble respect, not following
human arguments, which ought to be silent, but adhering firmly to divine revelation.

St. John Chrysostom, who, as you know, treated of the eucharistic mystery with such
nobility of language and insight born of devotion, instructing his faithful on one
occasion about this mystery, expressed these most fitting words: "Let us submit to
God in all things and not contradict Him, even if what He says seems contrary to our
reason and intellect; rather let His words prevail over our reason and intellect. Let us
act in this way with regard to the (eucharistic) mysteries, looking not only at what falls
under our senses but holding on to His words. For His word cannot lead us astray."[5]

The scholastic Doctors often made similar affirmations: That in this sacrament are the
true Body of Christ and His true Blood is something that "cannot be apprehended by
the senses," says St. Thomas, "but only by faith which relies on divine
authority. This is why, in a comment on Luke, 22,19: ('This is My Body which is given for
you'), St. Cyril says: 'Do not doubt whether this is true, but rather receive the words of
the Savior in faith, for since He is the truth, He cannot lie.'"[6]

Thus the Christian people, echoing the words of the same St. Thomas, frequently sing
the words: "Sight, touch, and taste in Thee are each deceived, the ear alone most
safely is believed. I believe all the Son of God has spokenthan truth's own word
there is no truer token."

In fact, St. Bonaventure asserts: "There is no difficulty about Christ's presence
in the Eucharist as in a sign, but that He is truly present in the Eucharist as He is in
heaven, this is most difficult. Therefore to believe this is especially
meritorious."[7]

Moreover, the Holy Gospel alludes to this when it tells of the many disciples of Christ
who, after listening to the sermon about eating His Flesh and drinking His Blood, turned
away and left Our Lord, saying: "This is strange talk, who can be expected to listen
to it?" Peter, on the other hand, in reply to Jesus' question whether also the twelve
wished to leave, expressed his faith and that of the others promptly and resolutely with
the marvelous answer: "Lord, to whom should we go? Thy words are the words of eternal
life."[8]

It is logical, then, that we should follow as a guiding star in our investigations of
this mystery the Magisterium of the Church, to which the Divine Redeemer entrusted for
protection and for explanation the revelation which He has communicated to us through
Scripture or tradition. For we are convinced that "what since the days of antiquity
was preached and believed throughout the whole Church with true Catholic Faith is true,
even if it is not submitted to rational investigation, even if it is not explained by
means of words."[9]

But this is not enough. Having safeguarded the integrity of the faith, it is necessary
to safeguard also its proper mode of expression, lest by the careless use of words, we
occasion (God forbid) the rise of false opinions regarding faith in the most sublime of
mysteries. St. Augustine gives a stem warning about this in his consideration of the way
of speaking employed by the philosophers and of that which ought to be used by Christians.

"The philosophers," he says, "speak freely without fear of offending
religious listeners on subjects quite difficult to understand. We, on the other hand, must
speak according to a fixed norm, lest the lack of restraint in our speech result in some
impious opinion even about the things signified by the words themselves."[10]

The Church, therefore, with the long labor of centuries and, not without the help of
the Holy Spirit, has established a rule of language and confirmed it with the authority of
the councils. This rule, which has more than once been the watchword and banner of
Orthodox faith, must be religiously preserved, and let no one presume to change it at his
own pleasure or under the pretext of new science. Who would ever tolerate that the
dogmatic formulas used by the ecumenical councils for the mysteries of the Holy Trinity
and the Incarnation be judged as no longer appropriate for men of our times and therefore
that others be rashly substituted for them? In the same way it cannot be tolerated that
any individual should on his own authority modify the formulas which were used by the
Council of Trent to express belief in the Eucharistic Mystery. For these formulas, like
the others which the Church uses to propose the dogmas of faith, express concepts which
are not tied to a certain form of human culture, nor to a specific phase of human culture,
nor to one or other theological school.

No, these formulas present that part of reality which necessary and universal
experience permits the human mind to grasp and to manifest with apt and exact terms taken
either from common or polished language. For this reason, these formulas are adapted to
men of all times and all places. But the most sacred task of theology is, not the
invention of new dogmatic formulas to replace old ones, but rather such a defense and
explanation of the formulas adopted by the councils as may demonstrate that divine
Revelation is the source of the truths communicated through these expressions.

It must be admitted that these formulas can sometimes be more clearly and accurately
explained. In fact, the achievement of this goal is highly beneficial. But it would be
wrong to give to these expressions a meaning other than the original. Thus the
understanding of the faith should be advanced without threat to its unchangeable truth. It
is, in fact, the teaching of the First Vatican Council that "the same signification
(of sacred dogmas) is to be forever retained once our Holy Mother the Church has defined
it, and under no pretext of deeper penetration may that meaning be weakened."[11]

For the inspiration and consolation of all, we wish to review with you, venerable
brothers, the doctrine which the Catholic Church has always transmitted and unanimously
teaches concerning the Mystery of the Eucharist.

We desire to recall at the very outset what may be termed the very essence of the
dogma, namely, that by means of the Mystery of the Eucharist, the Sacrifice of the Cross,
which was once offered on Calvary, is remarkably re-enacted and constantly recalled, and
its saving power exerted for the forgiveness of those sins which we daily commit.[12]

Just as Moses with the blood of calves had sanctified the Old Testament,[13] so also
Christ Our Lord, through the institution of the Mystery of the Eucharist, with His own
Blood sanctified the New Testament, whose Mediator He is. For, as the Evangelists narrate,
at the Last Supper "He took bread, and blessed and broke it, and gave it to them,
saying: 'This is My Body, given for you; do this for a commemoration of Me. And so with
the cup, when supper was ended. This cup, he said, is the New Testament, in My Blood which
is to be shed for you.'"[14] And by bidding the Apostles to do this in memory of Him,
He made clear His will that the same sacrifice be forever repeated.

This intention of Christ was faithfully executed by the primitive Church through her
adherence to the teaching of the Apostles and through her gatherings summoned to celebrate
the Eucharistic Sacrifice. As St. Luke carefully testifies, "These occupied
themselves continually with the Apostles' teaching, their fellowship in the breaking of
bread, and the fixed times of prayer."[15] From this practice, the faithful used to
derive such spiritual strength that it was said of them that "there was one heart and
soul in all the company of believers."[16]

Moreover, the Apostle Paul, who has faithfully transmitted to us what he had received
from the Lord,[17] is clearly speaking of the Eucharistic Sacrifice when he points out
that Christians, precisely because they have been made partakers at the table of the Lord,
ought not take part in pagan sacrifices. "Is not this cup we bless," he says,
"a participation in Christ's Blood? Is not the Bread we break a participation in
Christ's Body?.. . To drink the Lord's cup, and yet to drink the cup of evil spirits, to
share the Lord's feast, and to share the feast of evil spirits, is impossible for
you."[18] Foreshadowed by Malachias,[19] this new offering of the New Testament has
always been offered by the Church, in accordance with the teaching of Our Lord and
Apostles, "Not only to tone for the sins of the living faithful and to appeal for
their other needs, but also to help these who have died in Christ but have not yet been
completely purified."[20]

Passing over other citations, we recall merely the testimony rendered by St. Cyril of
Jerusalem, who wrote the following memorable instruction for his neophytes:

"After the Spiritual Sacrifice, the unbloody act of worship has been completed.
Bending over this propitiatory offering we beg God to grant peace to all the Churches, to
give harmony to the whole world, to bless our rulers, our soldiers, and our companions, to
aid the sick and afflicted, and in general to assist all who stand in need; and then we
offer the Victim also for our deceased holy ancestors and bishops and for all our dead. As
we do this, we are filled with the conviction that this Sacrifice will be of the greatest
help to those souls for whom prayers are being offered in the very presence of our holy
and awesome Victim."

This holy Doctor closes his instruction by citing the parallel of the crown which is
woven for the emperor to move him to pardon exiles: "In the same fashion, when we
offer our prayers to God for the dead, even though they be sinners, we weave no crown, but
instead we offer Christ slaughtered for our sins, beseeching our merciful God to take pity
both on them and on ourselves."[21]

St. Augustine testifies that this manner of offering also for the deceased "the
Sacrifice which ransomed us" was being faithfully observed in the Church at Rome,[22]
and at the same time he observes that the universal Church was following this custom in
her conviction that it had been handed down by the earliest Fathers.[23]

To shed fuller light on the mystery of the Church, it helps to realize that it is
nothing less than the whole Church which, in union with Christ in His role as Priest and
Victim, offers the Sacrifice of the Mass and is offered in it. The Fathers of the Church
taught this wondrous doctrine.[24] A few years ago our predecessor of happy memory, Pius
XII, explained it,[25] and only recently the Second Vatican Council enunciated it in its
treatise on the People of God as formulated in its Constitution on the Church.[26]

To be sure, the distinction between universal priesthood and hierarchical priesthood is
one of essence and not merely one of degree,[27] and this distinction should be faithfully
observed. Yet we cannot fail to be filled with the earnest desire that this teaching on
the Mass be explained over and over until it takes root deep in the hearts of the
faithful. Our desire is founded on our conviction that the correct understanding of the
Eucharistic Mystery is the most effective means to foster devotion to this Sacrament, to
extol the dignity of all the faithful, and to spur their spirit toward the attainment of
the summit of sanctity, which is nothing less than the total offering of oneself to
service of the Divine Majesty.

We should also mention "the public and social nature of every Mass,"[28] a
conclusion which clearly follows from the doctrine we have been discussing. For even
though a priest should offer Mass in private, that Mass is not something private; it is an
act of Christ and of the Church. In offering this Sacrifice, the Church learns to offer
herself as a sacrifice for all. Moreover, for the salvation of the entire world she
applies the single, boundless, redemptive power of the Sacrifice of the Cross. For every
Mass is offered not for the salvation of ourselves alone, but also for that of the whole
world.

Hence, although the very nature of the action renders most appropriate the active
participation of many of the faithful in the celebration of the Mass, nevertheless, that
Mass is to be fully approved which, in conformity with the prescriptions and lawful
traditions of the Church, a priest for a sufficient reason offers in private, that is, in
the presence of no one except his server. From such a Mass an abundant treasure of special
salutary graces enriches the celebrant, the faithful, the whole Church, and the entire
worldgraces which are not imparted in the same abundance by the mere reception of
Holy Communion.

Therefore, from a paternal and solicitous heart, we recommend to priests, who bestow on
us a special crown of happiness in the Lord, that they be mindful of their power, received
through the hands of the ordaining Bishop, of offering sacrifice to God and of celebrating
Masses both for the living and for the dead in the name of the Lord,[29] and that they
worthily and devoutly offer Mass each day in order that both they and the rest of the
faithful may enjoy the benefits that flow so richly from the Sacrifice of the Cross. Thus
also they will contribute most to the salvation of the human race.

By the few ideas which we have mentioned regarding the Sacrifice of the Mass, we are
encouraged to explain a few notions concerning the Sacrament of the Eucharist, seeing that
both sacrifice and Sacrament pertain inseparably to the same mystery. In an unbloody
representation of the Sacrifice of the Cross and in application of its saving power, in
the Sacrifice of the Mass the Lord is immolated when, through the words of consecration,
He begins to be present in a sacramental form under the appearances of bread and wine to
become the spiritual food of the faithful.

All of us realize that there is more than one way in which Christ is present in His
Church. We wish to review at greater length the consoling doctrine which was briefly set
forth in the constitution "De Sacra Liturgia."[30] Christ is present in
His Church when she prays, since it is He who "prays for us and prays in us and to
whom we pray as to our God."[31] It is He who has promised: "Where two or three
are gathered together in My name, I am there in the midst of them. [32]

He is present in the Church as she performs her works of mercy, not only because we do
to Christ whatever good we do to one of His least brethren,[33] but also because it is
Christ, performing these works through the Church, who continually assists men with His
divine love. He is present in the Church on her pilgrimage of struggle to reach the harbor
of eternal life, since it is He who through faith dwells in our hearts[34] and, through
the Holy Spirit whom He gives us, pours His love into those hearts.[35]

In still another genuine way He is present in the Church as she preaches, since the
Gospel which she proclaims is the Word of God, which is not preached except in the name of
Christ, by the authority of Christ, and with the assistance of Christ, the Incarnate Word
of God. In this way there is formed "one flock which trusts its only
shepherd."[36]

He is present in His Church as she governs the People of God, since her sacred power
comes from Christ, and since Christ, The Shepherd of Shepherds,"[37] is present in
the pastors who exercise that power, according to His promise to the Apostles:
"Behold I am with you all through the days that are coming, until the consummation of
the world."

Moreover, in a manner still more sublime, Christ is present in His Church as she offers
in His name the Sacrifice of the Mass, He is present in her as she administers the
sacraments. We find deep consolation in recalling the accurate and eloquent words with
which St. John Chrysostom, overcome with a sense of awe, described the presence of Christ
in the offering of the Sacrifice of the Mass: "I wish to add something that is
plainly awe-inspiring, but do not be astonished or upset. This Sacrifice, no matter who
offers it, be it Peter or Paul, is always the same as that which Christ gave His disciples
and which priests now offer: The offering of today is in no way inferior to that which
Christ offered, because it is not men who sanctify the offering of today; it is the same
Christ who sanctified His own. For just as the words which God spoke are the very same as
those which the priest now speaks, so too the oblation is the very same."[38]

No one is unaware that the sacraments are the actions of Christ, who administers them
through men. Therefore, the sacraments are holy in themselves, and by the power of Christ
they pour grace into the soul when they touch the body. The mind boggles at these
different ways in which Christ is present; they confront the Church with a mystery ever to
be pondered.

But there is yet another manner in which Christ is present in His Church, a manner
which surpasses all the others; it is His presence in the Sacrament of the Eucharist,
which is for this reason "a more consoling source of devotion, a more lovely object
of contemplation, a more effective means of sanctification than all the other
sacraments."[39]

The reason is clear; it contains Christ Himself and it is "a kind of perfection of
the spiritual life; in a way, it is the goal of all the sacraments."[40]

This presence is called "real"by which it is not intended to exclude
all other types of presence as if they could not be "real" too, but because it
is presence in the fullest sense: that is to say, it is a substantial presence by which
Christ, the God-Man, is wholly and entirely present.[41] It would therefore be wrong to
explain this presence by having recourse to the "spiritual" nature, as it is
called, of the glorified Body of Christ, which is present everywhere, or by reducing it to
a kind of symbolism, as if this most august Sacrament consisted of nothing else than an
efficacious sign, "of the spiritual presence of Christ and of His intimate union with
the faithful, members of His Mystical Body."[42] It is true that much can be found in
the Fathers and in the scholastics with regard to symbolism in the Eucharist, especially
with reference to the unity of the Church. The Council of Trent, restating their doctrine,
taught that the Savior bequeathed the blessed Eucharist to His Church "as a symbol
of that unity and charity with which He wished all Christians to be most intimately
united among themselves," and hence "as a symbol of that One Body of which He is
the Head."[43]

When Christian literature was still in its infancy, the unknown author of that work we
know as the "Didache or Teaching of the Twelve Apostles" wrote as follows on
this subject: "In regard to the Eucharist, give thanks in this manner:... just as
this bread was scattered and dispersed over the hills, but when harvested was made one, so
may Your Church be gathered into Your kingdom from the ends of the earth."[44]

The same we read in St. Cyprian, writing in defense of the Church against schism:
"Finally, the sacrifices of the Lord proclaim the unity of Christians, bound together
by the bond of a firm and inviolable charity. For when the Lord, in speaking of bread
which is produced by the compacting of many grains of wheat, refers to it as His Body, He
is describing our people whose unity He has sustained, and when He refers to wine pressed
from many grapes and berries, as His Blood, He is speaking of our flock, formed by the
fusing of many united together."[45]

But before all of these, St. Paul had written to the Corinthians: the one bread makes
us one body, though we are many in number the same bread is shared by all.[46]

While the eucharistic symbolism brings us to an understanding of the effect proper to
this Sacrament, which is the unity of the mystical Body, it does not indicate or explain
what it is that makes this Sacrament different from all others. The constant teaching
which the Catholic Church passes on to her catechumens, the understanding of the Christian
people, the doctrine defined by the Council of Trent, the very words used by Christ when
He instituted the Most Holy Eucharist, compel us to acknowledge that "the Eucharist
is that flesh of Our Savior Jesus Christ who suffered for our sins and whom the Father in
His loving kindness raised again."[47] To these words of St. Ignatius of Antioch, we
may add those which Theodore of Mopsueta, a faithful witness to the faith of the Church on
this point, addressed to the faithful: "The Lord did not say: This is a symbol of My
Body, and this a symbol of My Blood but: 'This is My Body and My Blood.' He teaches us not
to look to the nature of those things which lie before us and are perceived by the senses,
for by the prayer of thanksgiving and the words spoken over them, they have been changed
into Flesh and Blood."[48]

The Council of Trent, basing itself on this faith of the Church, "openly and
sincerely professes that within the Holy Sacrament of the Eucharist, after the
Consecration of the bread and wine, Our Lord Jesus Christ, true God and true Man, is
really, truly and substantially contained under those outward appearances." In this
way, the Savior in His humanity is present not only at the right hand of the Father
according to the natural manner of existence, but also in the Sacrament of the Eucharist
"by a mode of existence which we cannot express in words, but which, with a mind
illumined by faith, we can conceive, and must most firmly believe, to be possible to
God."[49]

To avoid misunderstanding this sacramental presence which surpasses the laws of nature
and constitutes the greatest miracle of its kind[50] we must listen with docility to the
voice of the teaching and praying Church. This voice, which constantly echoes the voice of
Christ, assures us that the way Christ is made present in this Sacrament is none other
than by the change of the whole substance of the bread into His Body, and of the whole
substance of the wine into His Blood, and that this unique and truly wonderful change the
Catholic Church rightly calls transubstantiation.[51] As a result of transubstantiation,
the species of bread and wine undoubtedly take on a new meaning and a new finality, for
they no longer remain ordinary bread and ordinary wine, but become the sign of something
sacred, the sign of a spiritual food. However, the reason they take on this new
significance and this new finality is simply because they contain a new
"reality" which we may justly term ontological. Not that there lies under those
species what was already there before, but something quite different; and that not only
because of the faith of the Church, but in objective reality, since after the change of
the substance or nature of the bread and wine into the Body and Blood of Christ, nothing
remains of the bread and wine but the appearances, under which Christ, whole and entire,
in His physical "reality" is bodily present, although not in the same way that
bodies are present in a given place.

For this reason the Fathers took special care to warn the faithful that in reflecting
on this most august Sacrament, they should not trust to their senses, which reach only the
properties of bread and wine, but rather to the words of Christ which have power to
transform, change and transmute the bread and wine into His Body and Blood. For, as those
same Fathers often said, the power that accomplishes this is that same power by which God
Almighty, at the beginning of time, created the world out of nothing.

"We have been instructed in these matters and filled with an unshakable
faith," says St. Cyril of Alexandria, at the end of a sermon on the mysteries of the
faith, "that that which seems to be bread, is not bread, though it tastes like it,
but the Body of Christ, and that which seems to be wine, is not wine, though it too tastes
as such, but the Blood of Christ draw inner strength by receiving this bread as
spiritual food and your soul will rejoice."[52]

St. John Chrysostom emphasizes this point, saying: "It is not the power of man
which makes what is put before us the Body and Blood of Christ, but the power of Christ
Himself who was crucified for us. The priest standing there in the place of Christ says
these words but their power and grace are from God. 'This is My Body,' he says, and these
words transform what lies before him."[53]

Cyril, Bishop of Alexandria, is in full agreement with the Bishop of Constantinople
when he writes in his commentary on the Gospel of St. Matthew: "Christ said
indicating (the bread and wine): 'This is My Body,' and 'This is My Blood,' in order that
you might not judge what you see to be a mere figure. The offerings, by the hidden power
of God Almighty, are changed into Christ's Body and Blood, and by receiving these we come
to share in the life-giving and sanctifying efficacy of Christ."[54]

Ambrose, Bishop of Milan, dealing with the Eucharistic change, says: "Let us be
assured that this is not what nature formed, but what the blessing consecrated, and that
greater efficacy resides in the blessing than in nature, for by the blessing nature is
changed." To confirm the truth of this mystery, he recounts many of the miracles
described in the Scriptures, including Christ's birth of the Virgin Mary, and then turning
to the work of creation, concludes thus: "Surely the word of Christ, which could make
out of nothing that which did not exist, can change things already in existence into what
they were not. For it is no less extraordinary to give things new natures than to change
their natures."[55]

However, there is no need to assemble many testimonies. Rather let us recall that
firmness of faith with which the Church with one accord opposed Berengarius, who, yielding
to the difficulties of human reasoning, was the first who dared deny the Eucharistic
change. More than once she threatened to condemn him unless he retracted. Thus it was that
our predecessor, St. Gregory VII, ordered him to pronounce the following oath:

"I believe in my heart and openly profess that the bread and wine which are placed
upon the altar are, by the mystery of the sacred prayer and the words of the Redeemer,
substantially changed into the true and life-giving flesh and blood of Jesus Christ Our
Lord, and that after the Consecration, there is present the true Body of Christ which was
born of the Virgin and, offered up for the salvation of the world, hung on the Cross and
now sits at the right hand of the Father, and that there is present the true Blood of
Christ which flowed from His side. They are present not only by means of a sign and of the
efficacy of the Sacrament, but also in the very reality and truth of their nature and
substance."[56]

These words fully accord with the doctrine of the mystery of the Eucharistic change as
set forth by the ecumenical councils. The constant teaching of these councilsof the
Lateran, of Constance, Florence and Trent whether stating the teaching of the Church
or condemning errors, affords us an admirable example of the unchangingness of the
Catholic Faith.

After the Council of Trent, our predecessor, Pius VI on the occasion of the errors of
the Synod of Pistoia, warned parish priests when carrying out their office of teaching,
not to neglect to speak of transubstantiation, one of the articles of the faith.[57]
Similarly our predecessor of happy memory, Pius XII, recalled the bounds which those who
undertake to discuss the mystery of transubstantiation might not cross.[58] We ourself
also, in fulfillment of our apostolic office, have openly borne solemn witness to the
faith of the Church at the National Eucharistic Congress held recently at Pisa.[59]

Moreover the Catholic Church has held on to this faith in the presence in the Eucharist
of the Body and Blood of Christ, not only in her teaching but also in her practice, since
she has at all times given to this great Sacrament the worship which is known as Latria
and which may be given to God alone. As St. Augustine says: "It was in His flesh that
Christ walked among us and it is His flesh that He has given us to eat for our salvation.
No one, however, eats of this flesh without having first adored it and not only do
we not sin in thus adoring it, but we would sin if we did not do so."[60]

The Catholic Church has always offered and still offers the cult of Latria to the
Sacrament of the Eucharist, not only during Mass, but also outside of it, reserving
Consecrated Hosts with the utmost care, exposing them to solemn veneration, and carrying
them processionally to the joy of great crowds of the faithful.

In the ancient documents of the Church we have many testimonies of this veneration. The
pastors of the church in fact, solicitously exhorted the faithful to take the greatest
care in keeping the Eucharist which they took to their homes. "The Body of Christ is
meant to be eaten, not to be treated with irreverence," St. Hippolytus warns the
faithful.[61]

In fact the faithful thought themselves guilty, and rightly so, as Origen recalls, if
after they received the Body of the Lord in order to preserve it with all care and
reverence, a small fragment of it fell off through negligence.[62]

The same pastors severely reproved those who showed lack of reverence if it happened.
This is attested to by Novitianus whose testimony in the matter is trustworthy. He judged
as deserving condemnation any one who came out of Sunday service carrying with him as
usual the Eucharist, the sacred Body of the Lord, "not going to his house but running
to places of amusement."[63]

On the other hand St. Cyril of Alexandria rejects as folly the opinion of those who
maintained that if a part of the Eucharist was left over for the following day it did not
confer sanctification. "For," he says, "neither Christ is altered nor His
Holy Body changed, but the force and power and vivifying grace always remain with
it."[64]

Nor should we forget that in ancient times the faithful, harassed by the violence of
persecution or living in solitude out of love for monastic life nourished themselves even
daily, receiving Holy Communion by their own hands when the priest or deacon was
absent.[65]

We say this not in order that there may be some change in the way of keeping the
Eucharist and of receiving Holy Communion which was later on prescribed by Church laws and
which now remain in force, but rather that we may rejoice over the faith of the Church
which is always one and the same.

This faith also gave rise to the feast of Corpus Christi which was first celebrated in
the diocese of Liege specially through the efforts of the servant of God, Blessed Juliana
of Mount Cornelius, and which our predecessor Urban IV extended to the Universal Church.
From it have originated many practices of Eucharistic piety which under the inspiration of
divine grace have increased from day to day and with which the Catholic Church is striving
ever more to do homage to Christ, to thank Him for so great a gift and to implore His
mercy.

We therefore ask you, venerable brothers, among the people entrusted to your care and
vigilance, to preserve this faith in its purity and integritya faith which seeks
only to remain perfectly loyal to the word of Christ and of the Apostles and unambiguously
rejects all erroneous and mischievous opinions. Tirelessly promote the cult of the
Eucharist, the focus where all other forms of piety must ultimately emerge.

May the faithful, thanks to your efforts, come to realize and experience ever more
Perfectly the truth of these words: "He who desires life finds here a place to live
in and the means to live by. Let him approach, let him believe, let him be incorporated so
that he may receive life. Let him not refuse union with the members, let him not be a
corrupt member, deserving to be cut off, nor a disfigured member to be ashamed of. Let him
be a grateful, fitting and healthy member. Let him cleave to the body, let him live by God
and for God. Let him now labor here on earth, that he may afterwards reign in
heaven."[66]

It is to be desired that the faithful, every day and in great numbers, actively
participate in the Sacrifice of the Mass, receive Holy Communion with a pure heart, and
give thanks to Christ Our Lord for so great a gift. Let them remember these words:
"The desire of Jesus Christ and of the Church that all the faithful receive daily
Communion means above all that through the sacramental union with God they may obtain the
strength necessary for mastering their passions, for purifying themselves of their daily
venial faults and for avoiding the grave sins to which human frailty is exposed."[67]

In the course of the day the faithful should not omit to visit the Blessed Sacrament,
which according to the liturgical laws must be kept in the churches with great reverence
in a most honorable location. Such visits are a proof of gratitude, an expression of love,
an acknowledgment of the Lord's presence.

No one can fail to understand that the Divine Eucharist bestows upon the Christian
people an incomparable dignity. Not only while the sacrifice is offered and the sacrament
is received, but as long as the Eucharist is kept in our churches and oratories, Christ is
truly the Emmanuel, that is, "God with us." Day and night He is in our midst, He
dwells with us, full of grace and truth.[68] He restores morality, nourishes virtues,
consoles the afflicted, strengthens the weak. He proposes His own example to those who
come to Him that all may learn to be, like Himself, meek and humble of heart and to seek
not their own interests but those of God.

Anyone who approaches this august Sacrament with special devotion and endeavors to
return generous love for Christ's own infinite love, will experience and fully
understandnot without spiritual joy and fruithow precious is the life hidden
with Christ in God[69] and how great is the value of converse with Christ, for there is
nothing more consoling on earth, nothing more efficacious for advancing along the road of
holiness.

Further, you realize, venerable brothers, that the Eucharist is reserved in the
churches and oratories as in the spiritual center of a religious community or of a parish,
yes, of the universal Church and of all of humanity, since beneath the appearance of the
species, Christ is contained, the invisible Head of the Church, the Redeemer of the World,
the Center of all hearts, "by whom all things are and by whom we exist."[70]

From this it follows that the worship paid to the Divine Eucharist strongly impels the
soul to cultivate a "social" love,[71] by which the common good is given
preference over the good of the individual. Let us consider as our own the interests of
the community, of the parish, of the entire Church, extending our charity to the whole
world, because we know that everywhere there are members of Christ.

The Eucharistic Sacrament, venerable brothers, is the sign and the cause of the unity
of the Mystical Body, and it inspires an active "ecclesial" spirit in those who
venerate it with greater fervor. Therefore, never cease to persuade those committed to
your care that they should learn to make their own the cause of the Church, in approaching
the eucharistic mystery to pray to God without interruption to offer themselves to God as
a pleasing sacrifice for the peace and unity of the Church, so that all the children of
the Church be united and think the same, that there be no divisions among them, but rather
unity of mind and purpose, as the Apostle insists.[72] May all those not yet in perfect
communion with the Catholic Church, who though separated from her glory in the name of
Christian, share with us as soon as possible with the helm of divine grace that unity of
faith and communion which Christ wanted to be the distinctive mark of His disciples.

This zeal in praying and consecrating one's self to God for the unity of the Church
should be practiced particularly by religious, both men and women, inasmuch as they are in
a special way devoted to the adoration of the Blessed Sacrament, according it homage and
honor on earth, in virtue of their vows.

Nothing has ever been or is more important to the Church or more consoling than the
desire for the unity of all Christians, a desire which we wish to express once again in
the very words used by the Council of Trent at the close of its decree on the Most Blessed
Eucharist: "In conclusion, the sacred synod with paternal love admonishes, exhorts,
prays and implores 'through the merciful kindness of our God'[73] that each and every
Christian come at last to a perfect agreement regarding this sign of unity, this bond of
charity, this symbol of concord, and, mindful of such great dignity and such exquisite
love of Christ Our Lord who gave His beloved soul as the price of our salvation and 'his
flesh to eat'[74] believe and adore these sacred mysteries of His Body and Blood with such
firm and unwavering faith, with such devotion, piety and veneration, that they can receive
frequently that super-substantial bread,[75] which will be for them truly the life of the
soul and unfailing strength of mind, so that fortified by its vigor[76] they can depart
from this wretched pilgrimage on earth to reach their heavenly home where they will then
eat the same 'bread of angels'[77] no longer hidden by the species which now they eat
under the sacred appearances."[78]

May the all-good Redeemer who shortly before His death prayed to the Father that all
who were to believe in Him would be one even as He and the Father were one,[79] deign
speedily to hear our most ardent prayer and that of the entire Church, that we may all
with one voice and one faith, celebrate the Eucharistic Mystery and, by participating in
the Body of Christ, become one body,[80] linked by those same bonds which He Himself
desired for its perfection.

And we turn with paternal affection also to those who belong to the venerable Churches
of the Orient, from which came so many most illustrious Fathers whose testimony to the
belief of the Eucharist we have so gladly cited in our present letter. Our soul is filled
with intense joy as we consider your faith in the Eucharist, which is also our faith, and
as we listen to the liturgical prayers by which you celebrate so great a mystery we
rejoice to behold your eucharistic devotion, and to read your theologians explaining or
defending the doctrine of this most august Sacrament.

May the Most Blessed Virgin Mary from whom Christ Our Lord took the flesh which under
the species of bread and wine "is contained, offered and consumed,"[81] may all
the saints of God, specially those who burned with a more ardent devotion to the Divine
Eucharist, intercede before the Father of mercies so that from this same faith in and
devotion toward the Eucharist may result and flourish a perfect unity of communion among
all Christians.

Unforgettable are the words of the holy martyr Ignatius, in his warning to the faithful
of Philadelphia against the evils of division and schism, the remedy for which lies in the
Eucharist: "Strive then," he said, "to make use of one form of thanksgiving
for the flesh of Our Lord Jesus Christ is one and one is the chalice in the union of His
Blood, one altar, one bishop."[82]

Encouraged by the most consoling hope of the blessings which will accrue to the whole
Church and the entire world from an increase in devotion to the Eucharist, with profound
affection we impart to you, venerable brothers, to the priests, Religious and all those
who collaborate with you and to all the faithful entrusted to your care, the apostolic
benediction as a pledge of heavenly graces.

Given at Rome, at St. Peter's, the third day of September, the Feast of Pope St. Pius
X, in the year 1965, the third year of our pontificate.